As part of CSHARP-457 a new typed Query builder was added to the C# driver. But it differs in some ways from the existing untyped driver (in addition to being typed). We should have a new simpler untyped Query builder that matches the new typed Query builder. In 1.5 we should continue to ship the existing Query builder and users could opt in to using the new Query builder. The existing Query builder should be marked as deprecated to help users migrate to the new Query builder.